An idea that I had, but not motivated enough to make.
A smart smoke alarm that opens the door and calls your pet with your recorded voice to go outside. Smart so that it can be set to only go off when you’re away (I don’t want my dogs running out every time I screw up in the kitchen.)
That might not be super difficult if you were able to train a smart assistant what a fire/smoke/CO detector sounded like. When >3 chirps are detected play myvoice.wav. Even easier if you could hardwire the circuit in the detector to the speaker. Sounds totally doable with a RaspberryPi or similar.